For the final project for IPD 501, Vehicle, I teamed up with Spencer Penn, Joe McCloskey, Diego Traviezo, Devin Caplow-Munro, Pele Collins , Mike Cesarano, and Brendan Stoeckl. The assignment was to make a ground vehicle, and we decided to make a three wheeled drag racer. I was responsible for the body design, manufacturing, and painting. Along with Joe and Diego, I designed and manufactured the carbon fiber chassis the front suspension mounting assembly. As part of the chassis design, I created the final CAD assembly and did all the renderings.
At the back of the vehicle, the large wheel is driven by a timing belt that is connected directly to a brushless DC motor with a gear ratio of 3:1.
Note how the wheels angle in as a result of the asymmetry in the four-bar linkage of the suspension. This increases the control in high velocity turns.
All finished and ready to race.
Design
My initial design. I’m much happier with where we ended up.
The second to last revision of the body design.
Sketches for the final design. The body changed again in the CAD to better fit the other parts.
The engineering drawing for the body mold. It took 9 layers of 3/4″ MDF to make.
Manufacturing
The mold after the rough cut with a 3/4″ Square Endmill.
The 3/4″ ball mill smooths out the ridges.
The finished mold is ready for the vacuum former.
The visualization of the tool path for the ball mill.
Pele tries to keep the dust under control. It was a losing battle.
Testing
Our initial target weight was 15 lbs. We were so successful at cutting weight, that we had to add lead fishing weights to limit acceleration and improve handling.
The guts. I’m probably proudest of the 3D printed electronics holders that use silicone hairbands to tightly strap down all the components.
A bit the worse for wear after about its first test drive. The MDF shell connectors broke, absorbing a lot of the impact. Everything else was unscathed.
We thermoformed three copies. We left one unpainted to show off the “behind the scenes”.
Everyone stands around sleepily admiring our success.
Carder C. House 